Fixture for grinding apparatuses

ABSTRACT

A fixture ( 10 ) for grinding apparatuses includes a base ( 12 ), a plurality of supporting components ( 14 ), and a pressure controlling apparatus ( 16 ). The base includes a cavity ( 126 ) containing a fluid medium ( 129 ), and the base defines a plurality of through holes ( 122 ) communicating with the cavity. One section of each supporting component is movably mounted in a through hole, and an end of each supporting component is exposed through its respective through hole and is configured for supporting an apparatus to be ground. The pressure controlling apparatus is connected to the base and facilitates selectable adjustment of a pressure of the medium.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to fixtures for grindingapparatuses and, more particularly, to a fixture for grindingapparatuses which prevents workpieces from being damaged.

2. Description of Related Art

Many kinds of workpieces need to be ground into an appropriate shapebefore use. When the workpieces are ground using grinding apparatuses,fixtures are used to hold the workpieces. Magnetic and mechanical clampsare widely used in grinding procedures.

Referring to FIG. 1, a typical magnetic clamp 40 fixes a workpiece 50magnetically. A grinding wheel 60 grinds a surface of the workpiece 50flat. However, usually a portion contacting with the magnetic clamp 40of the workpiece 50 is not flat. Therefore, magnetism between themagnetic clamp 40 and the workpiece 50 is distributed unevenly, and theworkpiece 50 is more likely to be deformed by uneven magnetic forcesacting between the magnetic clamp 40 and the workpiece 50 and by actionof the grinding wheel 60, when the workpiece 50 is ground. After theworkpiece 50 is ground and released from the magnet, the resultingground surface may be uneven. Thus, the typical magnetic clamp 40 tendsto be unsuitable for precision manufacturing.

If the workpiece 50 is fixed by a mechanical clamp when being ground,the workpiece 50 is even more likely to be deformed, the ground planebeing similarly distorted after the workpiece 50 is released from theclamp.

Therefore, a new fixture for grinding apparatuses is desired in order toovercome the above-described shortcomings.

SUMMARY OF THE INVENTION

In a preferred embodiment thereof, a fixture for a grinding apparatusesincludes a base, a plurality of supporting components, and a pressurecontrolling apparatus. The base includes a cavity containing a fluidmedium, and the base further has a plurality of through holes definedtherein, in communication with the cavity. One base-mounted end of eachsupporting component is movably mounted in a respective through hole ofthe base, and another supporting end of each supporting component isexposed through its respective through hole. The pressure controllingapparatus is connected to the base and controls pressure of the medium.

Other advantages and novel features will become more apparent from thefollowing detailed description when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the fixture can be better understood with reference tothe following drawings. The components in the drawings are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the fixture. Moreover, in thedrawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a schematic view of a workpiece being ground by a grindingwheel and being fixed by typical magnetic clamp;

FIG. 2 is a schematic view of a fixture, in accordance with a preferredembodiment;

FIG. 3 is a cutaway view of the fixture along the line III-III in FIG.2; and

FIG. 4 is a working schematic view of the fixture, in accordance withthe preferred embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings in detail, FIG. 2 shows a fixture 10, inaccordance with a preferred embodiment. The fixture 10 includes a base12, a plurality of supporting components 14, and a pressure controllingapparatus 16. The pressure controlling apparatus 16 cooperates with thebase 12 and the supporting components 14 to secure a workpiece 20, asrepresented in FIG. 4.

Also, referring to FIG. 3, the base 12 includes a working surface 120,two supporting blocks 124, and a cavity 126. The supporting blocks 124are respectively mounted on two opposing sides of the working surface120. The base 12 defines a plurality of through holes 122 on the workingsurface 120, between the two supporting blocks 124. The through holes122 communicate with the cavity 126. The base 12 also defines aconnecting hole 128 formed in a side face thereof, and the connectinghole 128 communicates with the cavity 126 and the outside of the base12. Some fluid medium 129 (schematically shown) is contained in thecavity 126. The medium 129 can be a liquid, such as oil or anotherhydraulic liquid, or a gas, such as compressed air. The medium 129 couldinstead, potentially, be a mixture of a solid powder and a fluidcarrier, the solid component helping to support the supportingcomponents 14 and the nature of the suspension offering fluidproperties.

Each supporting component 14 includes a piston 142, a central supportingpole 144, and an arcuate head portion 146. One end of the supportingpole 144 carries the piston 142, and the other end of supporting pole144 carries the head portion 146. Each end of the supporting pole 144carrying a respective piston 142 is movably mounted in one through hole122 and faces the cavity 126 and the medium 129 therein. Meanwhile, eachend of the supporting pole 144 with a respective head portion 146thereon is exposed out of the working surface 120, through itsrespective through hole 122 (i.e., exposed above both the workingsurface 120 and its respective through hole 122). Each supporting pole144 is slidably mounted in its respective through hole 122. Thus, byselectively sliding a supporting pole 144 of a given supportingcomponent 14, the vertical position of the head portion 146 of eachsupporting component 14 can be adjusted. Beneficially, a low-friction,clearance fit exists between a given supporting pole 144 and thecorresponding through hole 122, to promote efficient motion therebetweenand to reduce the potential for friction. It could also proveadvantageous for both the piston 142 and the head portion 146 to have adiameter in excess of that of the through hole 122, to preventaccidental dislodging of a given supporting component 14 duringoperation.

The pressure controlling apparatus 16 includes a motor 160, a pipeline161, and a valve 162. One end of the pipeline 161 is connected with themotor 160. The valve 162 is mounted in the pipeline 161. The motor 160(i.e., a hydraulic pump) is configured for communicating with a fluidand adjusting the pressure associated therewith.

In assembly, one end of the pipeline 161 is connected to the base 12 andis aligned with the connecting hole 128. The base 12 is connected to thepressure controlling apparatus 16, via the connecting hole 128 and thepipeline 161, and the valve 162 is opened. In this way, the pressurecontrolling apparatus 16 can adjust pressure of the medium in the cavity126. In particular, this pressure adjustment can be achieved by usingthe valve 162 to selectively control the medium flow into or out of thecavity 126.

Referring to FIG. 4, when the fixture 10 is used to fix the workpiece20, two opposite ends of the workpiece 20 are respectively placed on thetwo supporting blocks 124, and the mid portion of the workpiece 20 issupported by the supporting components 14. When the workpiece 20 ispressed or attracted (e.g., via magnetism or gravity) towards the base12, a pressure of the medium is kept within an appropriate range by thepressure controlling apparatus 16. Furthermore, a length of the exposedportion of each supporting portion 14 can be adjusted using pressure ofthe medium to correspond to the place in which the head portion 146 ofthe supporting portion 14 is brought into contact with the workpiece 20.In this way, the supporting components 14 support the workpiece 20 witha symmetrical supporting force and are able to correspond, as a group,to the shape of the work piece 20. Because of this support control,distortion of the workpiece 20 is prevented. When pressure of the mediumis adjusted to a preferred value, the valve 162 is closed, and thepressure of the medium 129 is stabilized.

Additionally, the base 12 can be magnetic and thus able to attract andhold a ferromagnetic workpiece 20 thereon. The supporting blocks 124 canpotentially be omitted.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present invention have been setforth in the foregoing description, together with details of thestructure and function of the invention, the disclosure is illustrativeonly, and changes may be made in detail, especially in matters of shape,size, and arrangement of parts within the principles of the invention tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed.

1. A fixture for grinding apparatuses, comprising: a base including acavity containing a fluid medium, the base having a plurality of throughholes defined therein, the through holes each communicating with thecavity; a plurality of supporting components, a central portion of eachsupporting component being movably mounted in a through hole, and asupport end of each supporting component being exposed above itsrespective through hole and above the base; and a pressure controllingapparatus connected to the base and configured for adjusting a pressureof the medium.
 2. The fixture as claimed in claim 1, wherein thepressure controlling apparatus includes a pump and a pipeline, one endof the pipeline is connected with the pump.
 3. The fixture as claimed inclaim 2, wherein the base defines a connecting hole, the base beingconnected to the pressure controlling apparatus via the connecting holeand the pipeline.
 4. The fixture as claimed in claim 2, wherein thepressure controlling apparatus includes a valve, the valve is mounted inthe pipeline.
 5. The fixture as claimed in claim 1, wherein the mediumis comprised of one of a liquid and a gas.
 6. The fixture as claimed inclaim 1, wherein the central portion of each supporting componentdefines a corresponding supporting pole, and a support end of eachsupporting component defines a head portion, each head portion beingcarried by a respective supporting pole.
 7. The fixture as claimed inclaim 1, wherein the base is magnetic and is thereby able to attract aferromagnetic workpiece theretoward.
 8. The fixture as claimed in claim1, wherein the base includes a working surface and two supportingblocks, the supporting blocks are respectively mounted on two oppositesides of the fixture, with the working surface extending therebetween,and the through holes are defined within the working surface.
 9. Afixture for grinding apparatuses, comprising: a base including a workingsurface and a cavity containing a fluid medium; a plurality ofsupporting components configured for supporting workpieces, one sectionof each supporting component being exposed out of the working surface,and length of the exposed section of each supporting portion is adjustedby changing a pressure of the medium; and a pressure controllingapparatus configured for adjusting the pressure of the medium.
 10. Thefixture as claimed in claim 9, wherein the pressure controllingapparatus includes a pump and a pipeline, and one end of the pipeline isconnected with the pump.
 11. The fixture as claimed in claim 10, whereinthe base has a connecting hole defined therein, the base being connectedto the pressure controlling apparatus via the connecting hole and thepipeline.
 12. The fixture as claimed in claim 10, wherein the pressurecontrolling apparatus includes a valve, and the valve is mounted in thepipeline.
 13. The fixture as claimed in claim 9, wherein the medium iscomprised of one of a liquid and a gas.
 14. The fixture as claimed inclaim 9, wherein the base defines a plurality of through holescommunicating with the cavity, each supporting component includes apiston, a supporting pole, and a head portion, one end of the supportingpole carries the piston, and another end of the supporting pole carriesthe head portion.
 15. The fixture as claimed in claim 14, wherein eachend connecting with a piston faces the cavity, and each end with a headportion is exposed above the working surface.
 16. The fixture as claimedin claim 9, wherein the base is magnetic and is thereby able to attracta ferromagnetic workpiece theretoward.
 17. The fixture as claimed inclaim 9, wherein the base includes two supporting blocks, the supportingblocks are respectively mounted on two opposite sides of the workingsurface, with the working surface extending therebetween, and thethrough holes are defined in the working surface between the twosupporting blocks.